Spark-plug.



' w. WILLEN.

` SPARK-PLUG. APPLICATION FILED JUNEZ, |915.

Patented Nov. 20, 1917'A inve-nto@ l. William magg @Umweg f WALL'ACEWILLETT, 0F EAST ORANGE, NEW JEBIISEY.

SPARK-PLUG'.

' Specication of Letters Patent. i Patentd NOV, 20, 1917,

Application led .T une 2, 1915. Serial No. 31,548.

To allwhomvz't may concern.'

Be it -known that I,' WALLACE WILLE'rr, a

citizen'y of the United States; and resident of East Orange, inthecounty of Essex and State of New Jersey, have invented certain new anduseful Improvements in Spark- Plugs, of which thel following is aspecificatlon. My invention relates to improvements in s park plugsofthe type particularly desi'gned to be mounted on internal combustionengines to produce the iiring spark in the combustion Vvchamber. v

The sparking points or electrodes of spark plugs now in general usefrequently become fouled and sometimes short circuit'ed by the depositof carbon on the sparking surfaces.

It is the present practice when a. spark plug becomes fouled either toremove one of the electrodes from the plug without unscrewing the plugfrom the engine, or to unscrew the entire plug from the englne casing.By the former plan the sparking surface or sur-Y faces .on only one sideof the circuitare -thread to wear the threads in the engine cleaned. Bythe latter plan the threads in the engine casing are subjected vtoconsiderableA wear. This wear is cumulative in the engine casing,vbecausev the plugs are replaced from time to time as they wear out, andtherefore each fresh plug presents a new casing.' VBy either plan it isnecessary to replace -the entire plug whenever a plug is worn out. y

The object of my invention is to provide a simple form of spark plug ofreadily demountable parts, the `outer containin shell or casing of whichmay be detachalSi/l cured in the wall of the combustion chamber with thevelectrodes and insulating member thereof constituting a removable unit,for insert in andfrcnioval from the shell. By this construction'all ofthe sparking surfaces `may be removed vfor cleaning without disturbingthe shell Ascrewed into the engine "casing, and in order to replace adefective plug it isonlyl necessary to substitute one or more of theparts ofthe demountable unit without dlsturbing the shell which isscrewed into the engine casing. i

Various other objects and advantagesy of the invention will beinpartobvious from an inspection of the accompanying` drawing and inpartfwillhe more *fully set forth in ,forth and claimed. f

vention shown mounted in position in'th i 'length to form a cvlilidrical flange 20 de-,

`the following particular." description of one f orm of mechanismembodying my vinvention, and the invention 'also consists in certain newand novel features of construction and 'combination of parts hereinafterset In the drawings: I v l 'Figure l is a sectional View taken axiallythrougha preferred embodiment of my inwall of a combustion chamber;

F1g.`2 is an enlarged end view of the sparking end of thespark plug; and

Figs. 3 and l are each compound views Y showing a side elevation and anend view respectively of the twofspark gap forming members.

In the following description and-inthel claims, arts will ,V beidentiedby specific namesV or convenience` of expression ibut theyareintended to bey as generic in their i application to similarl parts asthe art will permit.

In the drawings there is shown a ortion 5 of the wall outlining the comnstion chamber of an engine. j The wall is provided. with a. screwthreaded' opening 6 for the in'- sertion of a spark plug"as is usualwith de-fie vices of this character. A spark plug 7. isffyl inserted-inthis opening and comprises arab shell container 8 having a reducedend-M1;

screw-threaded into engagement with the. 1" opening 6. This shell `isprovided with a bore v10, the upper end of which is screw threaded asshown atll, the lower end of which' is frusto-conical as shown' at 12with the smaller end adjacent the inner end\"'of the shll, and theintermediate portion of the bore cylindrical as shown at 13.A Thefrustoconical portion 1'2 isreduced from the cylindrical portion to`form a shoulder 14 providing a seat for a packing ring l5. The lowerend of the shelhis concaved to form an electrode containing-,recess 16.y The bore is adaptedto contain a remov' able'unit comprising thi-eeelements. an insulatingcore 17 and 'tworco-aeting spark gap formingmembers 1S and 19 carried thereby. The insulating core 17 is preferablyformedV of porcelain and enlarged" intcrmediateitsl signed to fit withinthe cylindrical portion' 13 of the boreand tooverlap the shoulder 14;;Opposite sldes of the flange are rounded lower end with substantiallythe saine anglev into the end portions of the core. The lower portion ofthe core is tapered towardl its of taper 'as the frusto-conieal portion12 of the bore. y

The member 18 is in the form of a con- Y ducting rod which extendslongitudinally through the core 17, projects beyond oppo- .site ends ofthe same and has its lower end provided with a plurality ofelectrodes'21, which, in this embodiment of the inventlon, are show-n tobe three spheres projecting laterally from the rod and arranged 120apart in t'he'form of a circle. The upper end of the conducting rod isscrew-threadedY as -shown at 22 and co-acts with the cap 23 fittingtheupper end of the core and with the nut 26 to form the usual bindingpost.

The member 19 is formed of a frustoconical sleeve 27 ydesigned to befitted to the i tapered portion of the core with a frictionally tightlit. i The upper end of the sleeve is formed into an outturned flange 2Sdesigned to fit between the curved face of the iange 2O and the ring 15.The small lower end of the sleeveV 27 is provided with a plurality ofelectrodes 2f), in this embodiment of the invention shown to be three innumber, projecting downwardly N and slightly.

inwardly from the end of the sleeve'and adapted to be disposed betweenthe electrodes 21 to form six spark gaps as shown lin Fig. 2, with eachelectrode disposed between two electrodes of opposite polarity.

The removable unit is positioned in the shell with the electrodes in therecess 16 and is removably held in place by a bushing 30 engaging theouter threaded end 11 oi the bore. This bushing has a rounded end '31,designed to engage the rounded top vof the flange 2O to force the unitinto engagement vwith the packing ring 15.

Should .it be desn'ed'to clean the el eclrodes the bushing is unscrewcdand the unit including the electrodes and insulating cere is simplylifted out of the shell container 8 leaving the shell container inA itsscrewthreaded engagement with the engine casing. This provides a readyaccess to both sets of electrodes while mounted in.' their.

, spark gap'forming position, but should 4it be desired to separate theelements. forming the removable unit itis merely necessary to loosen thenut and. washer forming the binding post and the conducting rod may bewithdrawn from the core.- The sleeve may then be pulled off thecore vandthe parts separately cleaned.

-When assembled the position of the electrodes relative to each othermay be varied` from a pos1tion exteriorly of the engine casing byrotating the cap 23 which will raise or lower the electrodes 21-relative to the electrodes 29 and there is thus provided a.self-,cleaningconstruetion.

ing and'in this way the threads are not worn A and the spark plug isalways securely mounted in place. Either of the electrodes may beremoved for cleaning or renewal without disturbing the portion of theplug which is screwed into theengine casing. But even if the entire plugis removed and replaced when it is worn out, the threads in the enginecasing will not be materially worn, because this replacement does nottakeplace very frequently.

While I have shown and described, and have pointed out in the annexedclaims, certain vnovel features of my invention, it will be understoodthat various omissions, substitutions and changes inthe form and detailsof the device illustrated and in its opsoY eration may be made by thoseskilled in the art withoutl departing from the spirit of the invention.

Having thus described my invention, I A

claim:

1. In a spark cluding a sleeve provided with three ball electrodesextending from one end -thereof andspaced approximately 120 apart and amember positionedl within said sleeve and provided with three ballelectrodes positioned approximately 120 apart and each designed to bepositioned between adjacentv electrodes from the sleeve thereby to forma plug, a removable unit indemountable ringfof six spark gaps and stemsconnecting each ball electrode with itscorrelated sleeve or memberthereby to project the electrodes from their supports and with thecenters of the balls disposed in a. circle and equally spaced.

v2. A spark plug having a slightly concaved recess at one end, and aring of spaced apart electrodes protected within said recess,

said plug comprising a-containing shell, a sleeve itted in said shelland an insulating core fitted within said sleeve, said shell, sleeve andcore having recessed ends coactively designed to form the said electrode-containing recess, said sleeve provided with one of the electrodesforming said ring and a conductor lpassing through said core ,andprovided with another of the electrodes lforming said ring.

3, A demountable unit constituting part of a spark plug and designed toftin a. containing shell, said unit eomprisin 'a :member provided witha` pluralityof si ned to be arranged in a circle with eacho the ballpoints of one member disposed between a pair of ball points of the othermember.

' 4. A spark plug comprising a containing shell provided with means formounting the same in position, a unit frictionally connected to saidshell and comprising three ele- '.ments, two of said elementsconstituting conducting members and each of said two elements providedwith a ball point projection constitutingl a teminalpoint designedcoactively to form a plurality of spark gaps, and the third elementconstituting an insulation designed, when assembled with the conductingmembers to extend substantially the entire length of one of theconducting members,'except its terminal point, thereby to insure theinsulation of the members from each other, the upper end ofl said thirdelement extending above the other conducting Copies of this patent maybe obtained tor member thereby to provide anu-insulated haii' dle forremoving said third element.

5. A spark plug comprising a containing shell provided with afrusto-conical bore constituting a seat, a frusto-conical sleeve shapedto have its entire length lit in said seat with its upper'end spacedbelow the top of the shell and provided with an electrode extending fromthe reduced end thereof, lan insulating core having a portion designedto fit in said frusto-conical sleeve and to cover the wall forming thebore of the Sleeve and a rod passedthrough said core substann tiallycontained therein and provided vwith an electrode designed to coact withthe first named electrode to form a spark gap.

Signed at East Orange in the county of Essex and State of New Jerseythis twentyifthday of May, A. D., 1915.

. WALLACE WILLETT. Witnesses:

LYDIA H. THOMPSON, J. BooTE.

ve cents each, by addressing the fcomxnissionexI 9! Patenti. Washington,D. C.

